Chat Summary: STAC Hierarchies

Key Questions and Answers

1. How can you query an existing STAC catalog for photos within the spatial-temporal context of the Los Angeles fires?

   Use a bounding box (bbox) and temporal range (datetime) in the query. This can be done with a tool like stac-js, filtering photos that match the criteria.

2. How do you create a new STAC catalog for these photos?

   Query the existing catalog, collect the filtered items, and construct a new catalog object. Save it as a JSON file, linking the relevant items.

3. How can you organize multiple fire incidents within a parent-child relationship in STAC?

   Use a parent catalog to link to child catalogs for each incident (e.g., Palisade Fire, Houston Fire). Each child catalog contains items (e.g., photos, geospatial data) and links back to the parent.

4. What if a photo applies to multiple incidents?

   Options include:

   • Duplicating the item in both child catalogs for simplicity.
   • Creating a shared catalog for cross-incident items.
   • Using links in the item to cross-reference related catalogs.

5. Which approach is best for cross-referencing shared items?

   It depends on the context:

   • For user simplicity: Duplicate the item in relevant catalogs.
   • For centralized maintenance: Use a shared catalog.
   • For scalability and flexibility: Use cross-referencing via links.

Summary

This chat explored querying, organizing, and maintaining hierarchical relationships in STAC catalogs, particularly for wildfire-related geospatial data. The choice of approach depends on specific user needs and scalability goals.